Deepfakes have proven successful. It's not only cheaper but also more believable than CGI in most instances. The copy and paste of Rod Sterling is still Disney's gold standard. They could do it.
Some points I would like add.
I don't disagree, they could, my point was Disney does not like to spend that much, on anything anymore.
It is Rod Serling, not Rod Sterling. Common mistake but as a fan of his I try to correct it when I see it.
It is not that they can't do it, it is that they won't do it based on current trends for theme park spending. The tech has already been used over at Universal for a theme park attraction.
Also. Just for clarification, the Rod Serling Copy and Paste that you speak of was not putting his face somewhere. It was taking the background from an actual episode intro of The Twilight Zone and changing it. Impressive, especially for the time, but not the same. That is a clip and the sound alike is dubbed over and they cut when the mouth syllable would no longer work and it cuts to the close up of the elevator doors. Creativity over budget on top of all of that, that still works better than a deep fake.
Everything about the early 90s of Disney is the gold standard we wish we could get today. That is why we are getting a replacement for Splash Mountain's theme, rather than a new ride of that caliber and rarely get a new building with a new non cloned attraction.